The goal of IDS is to analyze events on the network and identify attacks. The increasing number of network security related incidents makes it necessary for organizations to actively protect their sensitive data with the installation of Intrusion Detection Systems (IDS). People are paid more attention on intrusion detection which as an important computer network security technology. According to the development trend of intrusion detection, detecting all kinds of intrusions effectively requires a global view of the monitored network, Here, discuss about new intrusion detection mechanism based on cloud computing, which can make up for the deficiency of traditional intrusion detection, and proved to be great scalable.